The effect of glucagon treatment upon hepatic mitochondrial function will be investigated. Studies will be carried out on possible hormonal alterations of the mitochondrial electron transport chain. Crossover experiments will be utilized to define specific components altered by hormonal treatment. Rates of electron transport in discrete portions of the chain will be measured by use of artificial electron donors and acceptors. The possible generality of increased mitochondrial function by hormones acting through increased cyclic AMP will be investigated.